It really is my choice isn't it. Let's just leave it at that. Find yourself another windmill to tilt at today. In over 25 yrs of flying RC I have never had a trottle seervo die or fail to work. I see you're into Gloom and Doom just as many are here. Enjoy your life of worry.

I with my man on this if we want to be truly redundent safe why dont we have two transmitters, so if one goes badd cut the other one on , could get costly for the 14mz guys!!!

Hey, this thread was very informative--I read every post. Here's what I learned (and I'm not telling anybody anything new, I'm just "thinking out loud" and posting for fun).

None of our flying organizations require a transmitter-operated electronic kill. The only requirement is that you can somehow shut down the engine from the Tx--whether electronically, throttle, etc. (I think there's also something about being able to turn off the ignition from a switch accessible outside the airplane.)

Being that we are talking about gas engines, we are talking about large airplanes with large, powerful engines with large propellers that, coupled with all the other gear, add up to a huge investment, and oh yea, can cause severe injury or death. All these factors beg the question "what's the best way to shut off the engine" and "what about redundancy?" (I know, you could take redundancy to extremes with redundant servos on all the rest of the controls, but this isn't as easy or practical.)

It sounds like conventional wisdom is to install some sort of electronic kill switch, but many are content with simply using "throttle cut" or the trim to close the butterfly on the carburetor and have had success with this method.

I wonder what all the sponsored, "big-name" pilots do? Maybe I'll have to ask around.

What's my point? I guess I don't have one except to say that I learned something here. Think I'll consider an electronic kill on my latest 50cc spark-ignition (gas) plane (maybe that RCAT RC-100).

Without any question all the sponsored "big name" pilots use whatever the sponsor manufactures?

Mike

Without much doubt, it is often true a sponsored pilot will select a particular brand of widget due to his sponsor. However, I don't often see competitive pilots elect to add a widget they feel they don't need or want. I've been fortunate to have met and flown with a few of top 10 pilots. I know that many use ignition kills but some do not. I don't recall any offhand who use a choke servo, but perhaps some do. I've not asked. Mike McConville and others have a pilot's forum..you can ask them. Honestly, it won't influence whether I choose to use one or not. Perception of both safety and convenience is a personal choice and we all have different experiences which cause us to be more, or less, risk averse.

If you've witnessed a runaway giant scale plane due to servo or firewall break-away failure (I saw one of each kill 2 planes, but fortunately nobody was injured), you'd likely be an advocate for ignition kill switches.

I am an advocate of using some remote method to kill the engine, especially on a large gas model. But I also am a huge advocate of the KISS principle. I dont like to use any additional equipment that doesnt add anythng, so I dont use an ignition kill switch because the engine can be killed just as effectivly but cutting the throttle. I always set up to kill my model so the engine will kill with low throttle trim.

Well, there's one big-name pilot!

Hi Mike!

Tim

Like I said from the beginning, it's personal choice issue and all those who stoop to name calling in this thread because of their beliefs are truly sad individuals.

25 years without a failure. You are either really good, really lucky or just about due. Murphy is a relentless person. I have been flying for over 30 years and just experienced my first throttle servo failure on my last flight of the day near dusk of a giant Piper Cub. After flying it it in a holding pattern at 1/3 throttle for over 30 minutes, the last 10 totally dark with no moon I felt pretty darn lucky to be able to land it followed by mostly stupid for not having a backup method to remotely shut down the engine. If it would have been any other type of plane than a big, slow yellow Cub, I don't think I could have seen it well enough to fly in those light conditions. So I was lucky and dodged Murphy once... I doubt I will be that lucky again so I am installing remote electronic kill switches as my choice to protect both my fellow fliers and my investment.

Nobody sad anything about not having a back up shutdown method and yes I've never had a throttle servo fail in over 25 yrs of flying. My large gas engine planes have a servo choke servo for backup way to shut down engine. Of course that's not even good enough for the gloom and doom crowd. All they say is what if that servo fails too. Pathetic way to think if you ask me. Why do I have to be due? If I continue to install my radio gear properly there is no reason to expect any less success than I've had in the previous 25 yrs. Of course I know you still think I'm due and that's your perogative. I just refuse to think that way.

Look at it this way. Let's make it mandatory that every pilot who flies RC has to have an expert pilot standing by on a Buddy Box to take over when he gets in trouble and is about to dumb thumb an aircraft into the ground, into the pitt area etc. Face it.....there will be thousands of airplanes crashed this way every year compared to the one or two throttle servo failures encountered in the same period. Makes sense to me. Let's get it going. Let's talk real gloom and doom.

SO...when you climb on your full scale private plane you stick your seat belt under the seat?

You've taken what he said completely out of context. Geeezzzz

Clearly Airtech didn't bother to read much of this thread nor my attempt to defuse the situation. So, I won't bother to get mad about taking him my words so incredibly out of context.

Net Net: Some people have not had scary experiences, or simply believe it will never happen to them, so they don't perceive a risk. They'll never use a safety device no matter what anybody on RCU says. I understand their position although I don't happen to agree with it.

Me? I'm a risk averse engineer. I have designed and developed too many products that can seriously injure or kill someone if something goes wrong.

Mike, I'm a fan of keeping it simple, too. But I also believe in using some form of engine cut-off device. that is redundant to a throttle servo. ...next time you see BJ (at Toledo, probably) ask him how he lost his FiberClassics Giles. Or what happened to his Comp ARF Extra.... I forgot which one had the throttle servo fail.

A choke servo is a good thing and certainly better than relying on throttle trim in case you lose a servo. I use a mini servo for choke when I use them, but mostly for convenience. They will work as long as a host of other bad things don't happen, like a firewall starting to pull out, battery/switch failure, crystal coming out, connectors loosening in the receiver, etc.. The thing that's nice about an RCATS ignition kill switch is that for $25 and 1/2 oz weight penalty, the switch open the contacts if you lose the receiver power or connection, thus killing your engine. It's cheap, light insurance.

With dual battery packs and dual switches, it is quite remote for the receiver to loose power.

If the firewall is pulled out and a choke servo is installed, the choke servo push-rod actually tries to pull the choke to close. The fuel line can be pulled out as well (maybe ignite a fire when the gas touches the hot muffler).

The real danger is loose control due to receiver failure. To which, a dual receiver system is desirable and if the throttle or choke servo is separately controlled by the two receivers, killing the engine is always possible.

Good points. I must be tired. BJ's plane Comp ARF actually had dual receivers, dual batteries/switches. Managed to lose the throttle servo. He didn't have a choke servo and he did not have a good day.

At least a choke servo will give you a secondary kill method. Personally I don't use them. I prefer the ignition kill. I still however use the throttle kill switch as my primary kill switch and have never had to use the ignition kill in an emergency. But for the price and ease of installation I use them in all my large scale planes. I guess that makes me a dooms dayer

Well I am sorry, please accept my apology. Aparently I misunderstood your statement.

no problemo

Agree. choke servo is useful and as effective as a kill switch.

So, I'm liking the idea of an ignition kill switch such as the RCATS, but what about the idea of keeping some sort of separation (10" - 12"?) between radio gear and engine components? I mean, if you have an RCATS (or any other brand) of electronic kill switch connected to your Rx, doesn't this then defeat the concept of keeping said spaceing?

Receiver to engine (and ignition system) separation is always a good practice. And as long as there is no source of RMI noise generated by the engine (i.e. loose spark plug, defective HV cable or iginition module) there should be no problem with using a kill switch like the RCAT. On the other hand the use of a Spread Spectrum (2.4 Ghz) system will completely eliminate engine noise as a problem source.

The best option (if you don't use a 2.4 system) is the use of an opticaly isolated Kill Switch unit (Fiber Optic cable) if you don't mind paying twice the cost of an RCAT unit. [link=http://www.smart-fly.com/Products/Ignition/ignition.htm]Smart-Fly's Ignition CutOff [/link] and [link=http://electrodynam.com/rc/EDR-107/index.shtml]ElectroDynamics Inc. EDR-107 Fiber Optic Kill Switch[/link] Switch fits that bill.

A choke servo probably is a better choice, in this case.

The more expensive optical switches like SmartFly (I have one as well) are more involved to install but work fine. They have both send/receive units plus fiber optic cable and do weigh a little bit more but they aren't "heavy". The RCATS RC-100 has worked well for me and is cheaper, simpler, lighter. If you have an especially noisy ignition or other problem you cannot solve, you might need to try to an optical switch.

I typically mount the RC-100 mid-way between the RX and the ignition battery, trying to keep the RC-100 physically as far from the receiver as possible. I've not experienced any RFI issues with it. The ignition module, battery, switch, is at least 12" away from the receiver, usually close behind the firewall. The RC-100 does have a direct connection into the receiver, but is physically located perhaps 8" away or more. When I first started with gas planes, I used to install an FM receiver in the plane first. This is to verify initial interference testing with an engine running to make sure there are no glitches during a range check. PCM can cover up a problem than can bite you later and I wanted to prove to myself that the switch and everything else was working glitch-free. Then I would switch to a PCM receiver for flying. Honestly, I've gotten lazy and usually just go with a PCM more recently, range check it, and then fly.

2.4 should be more immune, however it's still good practice to keep noise sources away from any receiver. I've got 2.4 in a heli, but not in one of my gas planes yet.

Oh, yea, I'm using 2.4 GHz FASST.

Thanks for the suggestions.

Tim